A student pulls horizontally on a block with a spring scale. The block reads 24.5 Newtons before the block starts to move. It reads 23.7 Newtons as she pulls the block at a constant velocity. How should she explain this?

Answer:

150 N

Explanation:

Force is equal to mass times acceleration.  50 kg accelerating at a mass of 3m/3² is undergoing a force of 150 m/s², or 150 Newtons

Answer:

displacement is the change from a starting point. she ends up back where she started so her displacement is zero meters although she traveled 24m in all.

To find the radius formed by melting the wire, you must start with this equation:

volume of wire = volume of sphere (since it is simply melted into a different shape, the volume would remain the same, equal)

πr²l = 4/3πr³

cancel π:

r²l = 4/3r³

3r²l = 4r³

r³ = (3r²l)/4

r³ = (3 × 3² × 200)/4

r³ = 1350

r = (cube root) of 1350

r = 11.052094....

r = 11.05 mm

divide by 1000 to get the answer in the unit meters:

r = 0.01105m

Answer: a process which a beam of light spread out as a result of the passing through a narrow aperture

Explanation:

Answer:

Since friction is a force it is measured in newtons

Hope this helps

Answer:

Winter

Explanation:

Answer:

idgaf

Explanation:

lol

The complete question is

A 45-kg child sits on a 3.2-kg tire swing. The tension on the rope is 470 N. The tree branch sags and the child's feet rest on the ground. If the tension in the rope is reduced to 220 N, what is the value of the normal force being exerted on the child's feet?

Answer:

Therefore the Normal force is being exerted on the child's feet is 252.36( 250N).

Explanation:

We are given

mass of child = 45kg

mass of the tire = 3.2kg

g = 9.8 m/s^2

We have the first case in which the tire is in swing so tension in that case will be which is the resultant force.

Fr = Resultant force

Ft =  Tension force

Fg= Gravitational force

Fr = Fg + Ft

0 = -mg + Ft

Ft = mg

   = (45+3.2)*9.8

   = 48.2 * 9.8

Ft = 472.36N  ( which is close to 470)

In the second case the child is in the rest position, The resultant force will be zero.

Fr = Ft + Fn + Fg  ( Normal force is denoted by Fn )

0 = Ft + Fn + Fg

Fn =  -Fg -Ft

Fn = mg -Ft

    = 472.36 - 220

Fn  = 252.36N  ( close to 250N)

Therefore the Normal force being exerted on the child's feet will be 252.36N.  

Answer: 121.2 m/s

Explanation:

Here we will use the conservation of energy.

We can write the total energy of an object as:

E = K + U

For this particular case we have:

K = kinetic energy = (m/2)*v^2

U = potential energy = m*g*h

where:

m = mass of the object.

g = gravitational acceleration = 9.8m/s^2

h = height at which the object is dropped, in this case 750m

v = velocity of the object.

Right when the packet is dropped, it's velocity is equal to zero, this means that there is no kinetic energy and only potential energy, then we have:

Ei = Ui = m*9.8m/s^2*750m = m*(7350m^2/s^2)

And when the object is about to hit the ground, h will be almost equal to zero, this will mean that we will have only kinetic energy, and because of the conservation of energy, this final energy must be the same as the initial energy, then we will have

Ei = Ef

m*(7350m^2/s^2) = Ef = Kf

m*(7350m^2/s^2) = (m/2)*v^2

We can divide by m in both sides to get:

(7350m^2/s^2) = (1/2)*v^2

√( 2*(7350m^2/s^2)) = v = 121.2 m/s

Then the velocity of the packet when it reaches the ground is 121.2 m/s

Answer:

Explanation:

Liluzivert

A) atoms

C) elements

D) molecules

Answer:

Mn(NO₃)₃

Explanation:

Manganese Nitrate solutions are categorized from moderate to high concentrated liquid solutions of Manganese nitrate.

This formula unit has Mn³⁺ cation and NO₃⁻ anions

Manganese nitrate comes before manganese carbonate that is used as a colorant and in making of fertilizers.

Answer:

the answer would be B

Explanation:

swelling is the result of the increased movement of fluid and white blood cells into the injured area.

Answer:

false

Explanation:

Answer:

it has the same mechanicals as a baseball

Explanation:

When the velocity of an object changes, it is acted upon by a force

Answer:

a. 3.68 m b. 0.61 m c. 3.07 m

Explanation:

a. What is the maximum height the ball reaches on the moon?

Using v² = u² - 2g'h where u = initial velocity of baseball = 12 m/s, v =  final velocity of baseball = 0 m/s (since it stops at maximum height), g' = acceleration due to gravity on moon = g/6 where g = acceleration due to gravity on earth = 9.8 m/s², so g' = 9.8 m/s²/6 = 1.63 m/s² and h = maximum height of ball on moon.

So, making h subject of the formula, we have

h = -(v² - u²)/2g'

substituting the values of the variables, we have

h = -((0 m/s)² - (12 m/s)²)/2(1.63 m/s²)

=  -(- 12 m²/s²)/2(1.63 m/s²)

= 6 m²/s²)/(1.63 m/s²)

= 3.68 m

b. What is the maximum height the ball reaches on the earth?

Using the same equation for the maximum height the baseball travels on the moon for that on the earth, the maximum height h' the baseball travels on the earth is given by  

h' = -(v² - u²)/2g where u = initial velocity of baseball = 12 m/s, v =  final velocity of baseball = 0 m/s (since it stops at maximum height),  g = acceleration due to gravity on earth = 9.8 m/s²and h' = maximum height of ball on moon.

substituting the values of the variables, we have

h = -((0 m/s)² - (12 m/s)²)/2(9.8 m/s²)

=  -(- 12 m²/s²)/2(9.8 m/s²)

= 6 m²/s²)/(9.8 m/s²)

= 0.61 m

c. What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?

The difference in the maximum height the ball reaches on the Moon compared to on Earth is d = h - h' = 3.68 m - 0.61 m = 3.07 m

Weight is the gravitational force an object experiences due to its mass and gravitational acceleration and the weight of an object on Earth is less than the weight of the same object on the Moon, but the mass remains the same. Thus, the correct options are B and C.

Mass is a scalar quantity. This is because it has magnitude only and no direction. Mass is commonly measured in the units of kilograms and grams.

Weight is a vector quantity. It has both the magnitude and it is directed towards the center of the Earth or other gravity well. Weight is commonly measured in the units of Newtons.

Weight is the gravitational force which an object experiences due to its mass and the acceleration due to gravity (g) and the weight of an object on the Earth is less than the weight of the same object on the Moon, but the mass remains the same as it is not dependent upon the gravity.

Therefore, the correct options are B and C.

Learn more about Weight here:

https://brainly.com/question/10069252

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Your answer is 0.30 seconds

Answer:

[tex]1\ \text{W/m}^2[/tex]

[tex]0.0039\ \text{W/m}^2[/tex]

Explanation:

[tex]I_1[/tex] = Intensity of sound at 2 m away

Sound level = 120 dB

[tex]r_1[/tex] = 2 m

[tex]r_2[/tex] = 32 m

[tex]I_0[/tex] = Threshold of sound = [tex]10^{-12}\ \text{W/m}^2[/tex]

Sound level is given by

[tex]dB=10\log (\dfrac{I_1}{I_0})\\\Rightarrow I_1=10^{\dfrac{dB}{10}}I_0\\\Rightarrow I_1=10^{\dfrac{120}{10}}\times 10^{-12}\\\Rightarrow I_1=1\ \text{W/m}^2[/tex]

The intensity of sound at 2 m away is [tex]1\ \text{W/m}^2[/tex]

[tex]I_1=\dfrac{P}{4\pi r^2}[/tex]

[tex]I\propto \dfrac{1}{r^2}[/tex]

[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\Rightarrow I_2=\dfrac{I_1r_1^2}{r_2^2}\\\Rightarrow I_2=\dfrac{1\times 2^2}{32^2}\\\Rightarrow I_2=0.0039\ \text{W/m}^2[/tex]

The intensity of the sound 32 m away is [tex]0.0039\ \text{W/m}^2[/tex]

Answer:

a

Explanation:

light can not pass through it completely

Answer:

a change in velocity can be a change in magnitude (or speed), but it can also be a change in direction.

Answer:

reference point

Explanation:

you can use a reference point to tell when an object is in motion or staying still. :)

Answer:it would make it thicker

Explanation:

Answer:

"The equation shows that the current in a circuit is inversely proportional to the resistance of the circuit. An increase in resistance would result in a decrease in current. And the factor by which the resistance increases is the same factor by which the current decreases."

Explanation:

Because it's just like wearing a glove/mitten when getting something out of the oven, because of the insulation from the glove/mitten, it reduces the heat that gets through into your hand, and it protects it. Just like what the "answer" says, it said that the resistance would decrease current.

Answer:

five dollars

Explanation:

im thick lol

Answer:

3763.2 Joules

Explanation:

GPE = mgh

m = 120kg

g = 9.8

h = 3.2 m

GPE = (120)(9.8)(3.2)

GPE = 3763.2 Joules

Answer:

Correct choice: b 4H

Explanation:

Conservation of the mechanical energy

The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):

E = U + K

The GPE is calculated as:

U = mgh

And the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

g = gravitational acceleration

h = height of the object

v = speed at which the object moves

When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:

[tex]U_1 = mgH[/tex]

When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:

[tex]\displaystyle U_2=\frac{1}{2}mv^2[/tex]

Since the energy is conserved, U1=U2

[tex]\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1][/tex]

For the speed to be double, we need to drop the snowball from a height H', and:

[tex]\displaystyle mgH'=\frac{1}{2}m(2v)^2[/tex]

Operating:

[tex]\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2][/tex]

Dividing [2] by [1]

[tex]\displaystyle \frac{mgH'}{mgH}=\frac{4\frac{1}{2}m(v)^2}{\frac{1}{2}m(v)^2}[/tex]

Simplifying:

[tex]\displaystyle \frac{H'}{H}=4[/tex]

Thus:

H' = 4H

Correct choice: b 4H